Water hardness in Kashiwa
65 mg/L moderately hard
Tap water in Kashiwa is moderately hard: 65 mg/L (3.8 gpg · 3.6 °dH · 6.5 °fH).
Source: Kashiwa City Waterworks, tap-water quality results (速報値) FY2025 Aug & Nov (2025-11) · data checked 2026-10-21
Range across supply zones: 58–71 mg/L.
Kashiwa takes about 80% of its water from the Edo River through the Kita-Chiba wide-area waterworks and the rest from city wells. The reported figure is 64.5 mg/L CaCO₃ (range 58.0 to 71.0 mg/L, 2025 data). Moderately soft water leaves visible deposits on kettles and taps over time, which regular descaling keeps in check.
Japanese waterworks report hardness (硬度) in mg/L CaCO₃; the standard is 300 mg/L and the target 10–100 mg/L.
Water data
| Total hardness | 65 mg/L |
|---|---|
| Utility | Kashiwa City Waterworks Department |
How Kashiwa compares
- Tap water in Kashiwa is 28 % harder than the median of the 228 cities we track in Japan (50 mg/L).
- By hardness it ranks 51 of 228 in Japan (1 = hardest); 78 % of these cities have softer water.
- In Chiba it is number 11 of 11 cities; the regional median is 76 mg/L.
- Nearest city with clearly softer water: Higashiyamato, 51 km away (48 mg/L).
- Nearest city with clearly harder water: Inzai, 17 km away (81 mg/L).
Ranking of the hardest and softest water in Japan →
What it means at home
- Visible kettle scale every few weeks; vinegar or citric acid is enough.
- Water heater and washing machine: some long-term scale; a scale inhibitor slows it.
- Dishwasher: medium salt setting.
- Softener optional; pays off mainly with a gas boiler or tankless heater.
How much salt will you use for softening?
Optional. A scale inhibitor or a small softener protects the heater; soap savings are modest.
Descale a coffee machine or kettle about every 3 months (typical manufacturer guidance for this hardness).
Estimates for planning, not a quote. Check your appliance manual for exact settings.
Dishwasher setting in Kashiwa
| Brand | Setting for this water |
|---|---|
| Bosch | H00 |
| Miele | 4 °dH |
| AEG / Electrolux | 1 |
| Beko | 1st |
| Hoover | S0 |
| LG | H0 |
From each brand's manual for the model family named in the source; your model may differ, so check its manual. All brands and how to change the setting →
FAQ
Is Kashiwa water hard or soft?
It is moderately hard: 65 mg/L as CaCO₃ (3.8 gpg, 3.6 °dH). The usual bands are soft < 60, moderately hard 60–120, hard 120–180 and very hard > 180 mg/L.
Is tap water in Kashiwa safe to drink?
Hardness is not a health issue; it is about limescale, taste and appliances. Mains water must meet national drinking-water standards. Japanese waterworks report hardness (硬度) in mg/L CaCO₃; the standard is 300 mg/L and the target 10–100 mg/L.
How many grains per gallon is Kashiwa water?
3.8 gpg, equal to 3.6 °dH, 6.5 °fH or 65 mg/L calcium carbonate.
What dishwasher salt setting should I use in Kashiwa?
For 65 mg/L (3.6 °dH) check your manufacturer's table: level 2–3.
Do I need a water softener in Kashiwa?
Not essential; a scale inhibitor protects the heater cheaply.
Source
Source: Kashiwa City Waterworks, tap-water quality results (速報値) FY2025 Aug & Nov (2025-11). Method: figure published by the water supplier. Kashiwa City Waterworks, tap-water quality results (速報値) FY2025 Aug & Nov · Outdated figure? Tell us